PHYTOCHEMICAL SCREENING AND ANTIMICROBIAL ACTIVITIES OF AQUEOUS EXTRACT OF VERNONIA AMYGDALINA (BITTER LEAF) AGAINST BACTERIA ISOLATED FROM WOUNDS

ABSTRACT The antibacterial activity of the aqueous extract of Vernonia amygdalina against bacteria isolated from wounds was studied. The results revealed the percentage occurrence of bacteria isolates obtained from wound samples revealed Staphylococcus sp. (35.3%), Pseudomonas sp. (26.9%), Enterococcus sp. (20.2%), Klebsiella sp. (10.1%) and Proteus sp. (7.6%). The result showed an inhibitory effect against Staphylococcus sp. at 100%, 75%, and 50% while 25% concentration recorded no inhibitory zone. Pseudomonas sp. and Proteus sp. recorded inhibitory zone at 100% while 75%, 50% and 25% recorded no zone of inhibition. Klebsiella sp. recorded inhibitory zone at 100% and 75% while 50% and 25% showed no inhibitory effect. Enterococcus sp. recorded no inhibitory zone at all tested concentration. The positive control disc (ampicillin) used, inhibited the growth of all test isolates while the negative disc (normal saline) showed no inhibition. All the extracts showed marked antibacterial activity but to varied zones of inhibition. The phytochemical screening of aqueous extract of Vernonia amygdalina revealed that flavonoids and saponins were moderately present while alkaloids, tannins and cardiac glycosides were found in trace amount. Vernonia amygdalina extract has excellent antibacterial activity against both gram positive and gram negative bacteria. From the studies, its clearly indicates that Vernonia amygdalina extract represents a novel source of antibacterial drugs, if the phytoactive components are purified and proper dosages are determined for administration.